The invention resides in an arrangement for controlling an internal combustion engine with an electronic engine control unit, an injector for injecting fuel into the combustion chambers of the internal combustion engine, communication lines for the transmission of signals between the electronic engine control unit and the injectors and an intelligent electronic component which forms a construction unit with each injector.
In an internal combustion engine, the fuel injection begin and the fuel injection end are important for the quality of the combustion and the composition of the exhaust gas of the engine. In order to maintain the legal emission limits, these two characteristic values are generally controlled by an electronic engine control unit. In practice, an internal combustion engine with common rail fuel injection faces the problem that there is a time delay between the start of the energization of the injector, the needle lift of the injector and the actual injection begin. The same applies for the injection end.
For avoiding this problem, the particular properties of an injector may be recorded in a storage device which is arranged at the injector. During the operation, these parameters are then read by the electronic control unit into the control unit and the desired control values are adapted to the particular injector. WO 97/23717A shows such a system.
The system can be further improved by detecting the injection needle position inductively by changing the PWM (Pulse Width Modulator) signal via a displacement gauge or an opto-electronic procedure. An opto-electronic solution is known from JP 58 206872. It includes a light sender, a light conductor and a receiver with a comparator. By way of the comparator, a change in the light intensity is evaluated. In this solution, the sender, the receiver and the comparator are arranged outside the injector. In addition to the additional expenditures for the cables, the penetrations of the light conductors through the injector housing are critical. Particularly in the high pressure area of the injector a faulty penetration may cause leakages and result in failure of the injector.
DE 102 29 414 A1 discloses an injector with an integrated optical needle stroke sensing arrangement. The stroke is determined by way of an optical sender-receiver unit, which detects and counts the number of light-dark changes. The accuracy of this arrangement is established via the number of the light-dark fields.
It is the object of the present invention to provide a reliable injector with an improved opto-electric position determination for the injector needle.